Eyesight-test cabinet.



PATENT-ED SEPT. 13, 1904.

W. A. ROSENBAUM.

EYESIGHT TEST CABINET.

APPLICATION FILED AUG.12. 1903.

N0 MODEL.

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UNITED STATES Patented September 13, 1904.

PATENT OEETEE.

IVILLIAM A. ROSENBAUM, OF NEW ROCHELLE, NEW YORK, ASSIGNOR TO THE MEYROWITZ MANUFACTURING COMPANY, A CORPORA- TION OF NEW JERSEY.

EYESlGHT-TEST CABINET.

SPECIFICATION forming part of Letters Patent No. 769,805, dated September 13, 1904.

Application filed August 12, 1903.

T0 aZZ whom, it may concern:

Be it known that I, WILLIAM A. Rosan- BAUM, a citizen of the United States, residing at New Rochelle, in the county of Westchester and State of New York, have invented certain new and useful Improvements in Eyesight- Test Cabinets, of which the following is a full, clear, and exact description.

This invention relates to apparatus for testing the eyesight to determine the character of lenses to be used in eyeglasses or spectacles.

The object of the apparatus is to provide a chart containing letters or characters arranged in rows and graduated in size which can be readily shifted from one position to another to expose the different rows of letters or characters to be read by the person whose sight is being tested. A single chart the entire face of which is exposed soon becomes familiar to the patient, and he does not rely wholly upon his vision in determining the letters and characters. It is therefore desirable to provide means for keeping covered certain portions of the chart while other portions are exposed and for changing the exposed portions at intervals in order that perfectly new characters may be presented to the patient at any stage in the test. It is furthermore desirable that a considerable number of changes be possible and that such changes be effected from a point distant from the chart and in such order as the operator may select.

With these objects in view the invention consists of the apparatus described and claimed in detail hereinafter with reference to the accompanying drawings, in which- Figure 1 is a front elevation of the testcabinet with parts broken away. Fig. 2 is a view of the band upon which the characters are carried. Fig. 3 is a vertical section near one side of the cabinet, and Fig. 4 is a diagram of the electric circuits.

A indicates a cabinet of general rectangular shape, but which may be as ornamental in design as desired, the essential feature of which is that the front plate a shall contain a plurality of horizontal oblong openings,

Serial No. 169,186. No model.)

preferably more than two, there being three shown in the drawings, lettered, respectively, a, a and a These openings are of graduated sizes to fit the letters which are to be exposed through them. Inside of the casing are arranged two guide-rollers b and b and a drum 0. Around the rollers and the drum is placed an endless band 6, which by reason of the location of the rollers band 6 is stretched back of the front plate of the cabinet and closely adjacent thereto. This band carries on its face rows of letters'or characters arranged in groups f, f, and f All the characters of any group are of the samesize; but those in the upper group are the largest, while those in the next group are somewhat smaller and thosein the succeeding groups successively smaller. The three groups shown correspond to the three openings in the front plate of the cabinet. Those in the group are to be displayed at times through the opening 6/, those in the group f are to be displayed in the opening (0 and those in the group f are to be displayed in the opening (4 If the first row of one group is displayed through the corresponding opening, then the first row of all of the other groups will be displayed through their respective openings, and the rows of characters are so spaced apart that when the band is shifted so that the second row of any group appears before its corresponding opening the second row of all the other groups will likewise appear before their respective openings. To obtain this motion of the band, I resort to an electromagnetic apparatus now to be described.

On the shaft of the drum 0 is a pinion c, engaging with a gear segment g, mounted upon an axis 9. This segment carries a softiron armature and on its hub there are a series of notches g into which the spring 9 may drop to hold the segment at a particular position. Arranged concentrically with the segment are three electromag-nets v1, c", and 71 suitably mounted upon a bracket 1', with their cores radially disposed from the axis 9. The armature g normally stands directly in front of the poles of one of these magnets, at

which position the segment is locked by the spring g. If the next adjacent magnet then becomes energized, the armature will be attracted by it and the segment moved in a corresponding direction until the armature stops in front ofthe pole of the active magnet, where it becomes locked, as before.

The electric circuits will be described in connection With the operation, which now follows: The cabinet is supposed to belocated at a point distant from the patient and the operating physician. At some point convenient to the physician will be located three pushbuttons or circuit-closers 1, 2, and 3, respectively. With thesegment g in the position shown in Fig. 4 we will assume that the first row of characters of each group is exposed through the openings in the front plate of the cabinet. These are used for a test of the eyes of thepatient, and after the usual trials the physician can bring an entirely new set of characters into view by touching the button 2. This will close a circuit from the battery B by Wire 4:, button 2, wire 5, magnet 2", wire 6, and wire 7 to battery. Magnet 2" then being energized will attract the armature and swing the segment on its axis, causing the drum 0 to rotate and move the band a proper distance to expose the second row of each group of characters at the openings of the cabinet. When another change is desired, the button 3 is touched and a similar circuit is closed through the magnet d and battery B, as can be easily traced. This exposes the third row of each group of characters. It now the physician wishes to return to the first row of each group, he will touch the buttons 2 and l in succession, or if he wishes to merely return to the second row he will touch only the button 2.

The drum cmay have projections upon it, as shown, to engage the belt and-prevent the shifting of its positionupon the rollers.

Having described my invention, I claim 1. An-apparatus for testing the eyesight, consisting of acasing havinga front plate provided with a number of openings incombination with a band arranged behind said openings and containing a number of groups of characters corresponding to said openings, the said characters of each group being arranged in more than two rows, a roller over which said band passes, gearing connected with said roller, an armature connected with said gearing, a number of electromagnets corresponding with the number of rows of characters in each group, each of which is adapted to actuate said armature and means for energizing said magnets successively at will, substantially as described.

2. An apparatus for testing the eyesight, consisting of a casing having a front plate provided with a number of openings in combina tion with a band arranged behind said openings and containing a number of groups of characters corresponding to said openings, the said characters of each group being arranged in more than two rows, a roller over which said band passes, gearing connected with said roller, an armature connected with said gearing, a number of electromagnets corresponding with the number of rows of characters in each group, each of which is adapted to actuate said armature and anumberof circuit-closers in series with the respectivemagnets and a battery whereby the magnets may be successively energized at will,substantially as described.

In witness whereofI subscribe my signature in presence of two witnesses.

WM. A. ROSENBAUM.

Witnesses:

WALDo M. CHAPIN, FRANK S. OBER. 

